When Tony Liu Kit-ming joined Hong Kong's police force in 1982, China was a taboo subject.
'There was much misunderstanding in the general public too,' he said. 'For example, people kept rumouring that there were people in Luohu Commercial City [a mall in Shenzhen] who would kill passersby and remove their organs for sale.'
The veteran police inspector - an enthusiastic supporter of national studies who has organised mainland study tours for colleagues - said Hong Kong civil servants' knowledge of the country had increased over the years, but still had room to grow.
Liu, chairman of the Hong Kong Police Inspectors' Association, said most civil servants took a 'utilitarian approach' towards training and attended only courses directly related to their positions; classes would be popular among police officers only if the titles carried the word 'policing'.
Liu has taken courses at Jinan University, the state-run Chinese Academy of Governance and the top two mainland universities, Peking and Tsinghua.
'In every class I gained some insight,' he said. 'The work of police needs a lot of common sense. For example, in cross-border fraud cases with either the defendant or the plaintiff being a mainlander, it helps if you understand more about the mainland.'